Outdoor and feral cats face serious dangers when exposed to freezing winter temperatures. Unlike their domesticated counterparts, these felines lack the comforts of a temperature-controlled home during the coldest months. Prolonged exposure to frigid conditions can lead to frostbitten ears and tails, hypothermia, respiratory infections, and even death. Providing an insulated, weatherproof shelter is crucial for helping feral colonies and stray cats survive the winter.
Outdoor cats tend to be resourceful, finding warmth underneath porches or in sheltered areas, but these spots offer minimal protection. A well-made winter shelter can literally make the difference between life or death for these cats. The shelter should maintain temperatures above freezing and allow cats to stay dry. Equally important is making sure it offers adequate ventilation and space for multiple cats if needed.
With some simple materials and a bit of effort, anyone can create a refuge that helps nearby strays and ferals endure the harsh winter weather. This guide will cover choosing the right location, essential insulation and heating elements, proper bedding, and tips for long-term maintenance and care.
Materials Needed
When building a winter cat shelter, the most important materials to use are insulating substances that will retain heat and keep the interior of the shelter warm. Some common materials that work well include:
Cardboard boxes – Cardboard is inexpensive, provides insulation, and is easy to cut and configure into a shelter shape. According to Alley Cat Advocates, cardboard boxes with flaps intact make good windbreaks.
Plastic storage bins – Plastic bins are durable, provide insulation, and have a waterproof quality. They can be lined with straw or another insulating material. This DIY cat shelter video demonstrates using a plastic storage bin.
Styrofoam coolers – Styrofoam coolers are excellent insulators and readily available. They can be lined and have entry holes cut into them. Old coolers in good condition work well for this purpose.
Other insulating materials like straw, bubble wrap, towels, and fleece blankets also help provide warmth. The key is using materials that trap air and don’t allow heat to escape.
Choosing a Location
When choosing a location for the winter cat shelter, it’s important to place it in an area protected from the wind and precipitation. According to the experts at Home and Roost, “If it is at all possible, try and place the cat house in a sunny spot. It will provide your cat or strays with a warm refuge away from the cold and wet weather.”
You’ll want to find a spot that gets sunlight during the day to help warm the interior of the shelter. Place the shelter against the side of a building or structure to block it from cold winds. Avoid low-lying areas that are prone to flooding or collecting water.
An ideal location is up off the ground (such as on a deck or patio) and tucked against the house or under an overhang. This will help keep the inside of the shelter dry during rain or snowstorms. Just make sure it’s not directly under an area where ice dams or heavy snow slides may occur.
Insulation
Proper insulation is crucial for keeping feral cats warm in the winter. The best materials to use are loose, dry fibers that allow cats to burrow in and retain body heat. Some top options include:
Straw – This is an ideal insulation material as it’s loose, dry, and enables cats to nestle down into it. Make sure any straw is fresh and dry. Damp straw can grow mold and be unhealthy for cats. Aim for at least 6 inches of packed straw in the shelter.1
Newspaper – Shredded newspaper makes good insulation when packed tightly into the shelter walls and ceiling. Make sure newspapers are dry. Change newspaper regularly as it compresses over time.2
Towels/blankets – These should only be used minimally as they retain moisture and get damp. Place towel or blanket layers towards the top of the insulation, not directly in the sleeping area.3
Aim for at least 4-6 inches of dry, loose insulation material throughout the shelter for adequate warmth.
Heating
Providing a heat source is important for keeping cats warm in cold winter weather. Some safe and easy heating options for a winter cat shelter include:
Self-heating mats – These mats contain a chemical reaction that generates heat when activated. They provide several hours of warmth and are safe around pets. Place a mat on the floor of the shelter.
Microwavable heat disks – You can purchase reusable plastic disks, heat them in the microwave, and place them in the shelter to provide warmth. Replace them with freshly heated disks 1-2 times per day as needed
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Bottles or bags of warm water – Fill sealable plastic bottles or bags with hot water and wrap them in towels or blankets. The trapped warmth will radiate into the shelter. Switch out with new hot water a few times a day.
Ventilation
Proper airflow is crucial for any outdoor cat shelter, especially in winter. Without ventilation, moisture can build up inside the shelter, creating an unhealthy environment for cats. Small vents or gaps should be incorporated near the top of the shelter to allow fresh air to circulate while still maintaining insulation (Safe Spaces: How to Successfully Set-up, … – New Age Pet).
The key is finding the right balance between ventilation and insulation. You’ll want holes large enough for airflow but small enough to retain heat inside the shelter. One recommendation is to add vents on just one side of the shelter. That way, wind and drafts come from only one direction instead of creating a tunnel effect (How To Make An Insulated Outdoor Cat House For Winter). The vents should be positioned near the top since warm air rises.
You can cut vents out of wood, plastic or even thick cardboard. Make sure the vents have a moisture barrier so rain and snow don’t get inside. Position them above where the cats will sleep so they don’t get a direct draft.
Bedding
The right bedding material is crucial for comfort and insulation in a winter cat shelter. According to this source, straw not hay provides the best bedding for outdoor cat houses to help cats stay warm and dry. Straw is lightweight, absorbent, and breathable. It wicks away moisture while retaining insulating air pockets. Make sure to use straw, not hay, as hay can contain dust and mold.
Towels, blankets, and old clothes/fabric can also be used but are not ideal. They tend to retain moisture and can get damp. If using fabrics, make sure to switch out bedding frequently to prevent cats from getting wet and cold. Thicker, more absorbent fabrics like polar fleece blankets work better than thin towels or sheets.
Waterproofing
Waterproofing is critical for an outdoor winter cat shelter. You’ll want to ensure no rain, snow or other moisture can seep into the shelter and get your cats wet. Here are some effective waterproofing techniques:
Line the interior with heavy plastic sheeting or tarps. Cut the material several inches wider than the interior dimensions so you can secure it tightly along the edges and seams. Use silicone caulk to glue down the edges of the plastic (source).
Seal all exterior joints and seams with silicone caulk, exterior acrylic latex caulk or other flexible outdoor sealant designed for weatherproofing. Pay particular attention to sealing up joints between walls and roof. Apply several layers to ensure water cannot penetrate (source).
Consider applying exterior waterproof sealant to the entire exterior surface for maximum protection. Multiple coats of exterior latex paint also helps seal and protect the exterior.
Install overhanging eaves around the entrance and roof edges to prevent rain from dripping directly into the opening.
Maintenance
Regular maintenance and upkeep is important for any outdoor cat shelter. The shelter should be cleaned out at least once a week to keep it free of dirt, feces, and other debris. Remove all wet and soiled bedding and replace it with fresh, dry bedding materials. Cedar chips or shavings make good bedding as they help absorb moisture and have a fresh scent cats enjoy. Shake out and replace the bedding fully every 4-6 weeks.
Inspect the shelter each time you clean for any damage or wear and tear. Look for chewing, claw marks, leaks, loose boards, etc. Make any needed repairs right away to ensure the shelter remains warm, dry and draft-free. Re-seal any leaks with silicone caulk. Replace any cracked or rotting wood. Secure any loose panels or roofing. Maintaining the shelter properly will extend its usable life and keep it a welcoming place for outdoor cats.
Check that ventilation openings remain clear and unobstructed. Clear away any cobwebs, leaves, ice, snow or other debris. Proper airflow is essential for temperature regulation and reducing odors. The shelter entrance should also be kept clear of any obstacles so cats can easily enter and exit. With regular upkeep and timely repairs, an outdoor cat shelter can provide felines with a safe refuge from the elements for many seasons.
Alternatives
Besides building a shelter, there are some other options to help keep stray and feral cats warm in the winter.
Heated bowls can provide cats with warm food and water. These bowls have a heating element built in to keep contents at an ideal temperature. Products like the K&H Pet Products Thermo Kitty Heated Bowl and Petkit Pura X Smart Heated Bowl are good options.
Heated mats give cats a warm place to rest outdoors. Mats like the K&H Pet Products Snuggle Safe Outdoor Heated Pet Mat or Aspen Pet Self-Warming Heated Cat & Dog Mat provide soothing warmth without electricity.
Letting the cat come indoors occasionally is another way to give it respite from the cold. Set up a safe space like a spare bathroom or mudroom where the cat can warm up when needed. Just be sure to follow proper introduction techniques if you have other indoor pets.